Acid regeneration of ion exchange resins for industrial applications

ABSTRACT

Methods and systems for acid regeneration of ion exchange resins are disclosed. Acid resins designed for use in a variety of cleaning application using a water source use a treated, softened, acidic water source according to the invention. Various methods of using the softened acidic water generated by acid regenerate-able ion exchange resins are disclosed to beneficially reduce spotting, filming and scale buildup on treated surfaces, reduce and/or eliminate the need for polymers, threshold reagents and/or rinse aids, and using protons generated in the acidic water effluent for triggering events useful in various cleaning applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional application of U.S. ProvisionalApplication No. 61/569,829, filed Dec. 13, 2011, which is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to methods and apparatus for the acid regenerationof ion exchange resins for use in various industrial cleaningapplications at a point of use. In particular, an acid regenerated resinis designed for use in any cleaning application using a water source toprovide a softened acidic water source exhibiting relatively lower totaldissolved solids (TDS). Various methods of using the softened acidicwater generated by acid regenerate-able ion exchange resins are alsodisclosed. In addition, the methods and apparatuses according to theinvention are further beneficial in reducing spotting and filming ontreated surfaces, preventing scale buildup on treated surfaces, reducingpolymers and threshold reagents necessary in a detergent source, andusing protons generated in the acidic water effluent for triggeringevents useful in various cleaning applications as disclosed herein.

BACKGROUND OF THE INVENTION

Various water treatment methods for decreasing hardness of water areknown and commercially employed. Detergents and other cleaning agentsoften contain numerous components to improve the cleaning activity ofthe detergent, including for example, components to counteract theeffects of water hardness. Hard water is known to reduce cleaningefficacy both by forming films on surfaces and reacting with detergentand other cleaning components, making them less functional in thecleaning process. Various methods for counteracting and/or eliminatingwater hardness have been implemented by those skilled in the art,including for example, adding chelating agents or sequestrants intodetersive compositions in amounts sufficient to handle the hardness ionsand/or softening a water source via ion exchange. Ion exchange can beused to exchange hardness ions, such as calcium and magnesium, in thewater with sodium or other ions associated with a resin bed in a watersoftening unit.

Various ion exchange methods are known by those skilled in the art. Mostcommonly, water is run through an exchange resin to adhere the hardnessions calcium and magnesium to a resin in the softener. However, when theresin becomes saturated it is necessary to regenerate the resin usinglarge amounts of sodium chloride dissolved in water. This regenerationprocess has numerous known disadvantages, namely requiring the use ofbriny solutions and chloride from added sodium chloride used to flushout the resin. Accordingly, when water softeners regenerate they producea waste stream that contains significant amounts of sodium, creating aburden on the system, e.g., sewer system, in which they are disposed of.The generated waste presents a multitude of downstream water re-useconcerns, including for example water re-use applications like potablewater usage and agriculture. Further, traditional water softeners add tothe salt content in discharge surface waters, which has become anenvironmental issue in certain locations. These and other limitations ofcommercially-available water softening methods are described in furtherdetail in U.S. patent application Ser. No. 12/764,621, entitled “Methodsand Apparatus for Controlling Water Hardness,” the entire contents ofwhich are hereby expressly incorporated herein by reference.

Accordingly, it is an objective of the claimed invention to developimproved methods and retrofitted systems for regenerating ion exchangeresins for use in various institutional and industrial applications.

A further object of the invention is to develop a system and methods forusing acid regenerate-able ion exchange resins to pre-treat water forthe various institutional and industrial applications, resulting in thereduced demand for polymers and threshold reagents in cleaningcompositions (e.g. detergents).

A further object of the invention is to improve ware wash and othercleaning application results through the application of softened acidicwater generated by acid regenerate-able ion exchange resins at a pointof use.

A still further object of the invention is to develop methods forapplying protons in a treated water source to trigger events, such asregeneration of the resins, dispensing additional detergent and/or othercleaning aids, and the like.

Still further, the invention sets forth methods and systems for reducingscale buildup, spotting and/or film formation by treating a water sourceusing an acid regenerate-able ion exchange resin.

BRIEF SUMMARY OF THE INVENTION

In an aspect of the invention, a system employing an ion exchange resinregenerated by an acid comprises: an inlet for providing a water sourceto a water treatment reservoir; a water treatment component housed inthe water treatment reservoir, wherein said water treatment component isat least one ion exchange resin to generate a treated water source byexchanging protons on said resin for dissolved cations including waterhardness ions and total dissolved solids in said water source, whereinthe treated water source is a softened, acidic, and low total dissolvedsolids (TDS) water; an outlet fluidly connected to the water treatmentreservoir; and a water delivery line to provide the treated water sourceto a cleaning application and/or storage reservoir.

In another aspect of the invention, a method for treating hard waterusing an acid regenerated ion exchange resin comprises: contacting ahard water source with a water treatment composition in a service cycle,wherein the water treatment composition comprises at least one ionexchange resin, wherein the ion exchange resin generates a treated watersource by exchanging protons on said resin for dissolved cationsincluding water hardness ions and total dissolved solids in said watersource, and wherein said ion exchange resin is regenerated using anacid;

generating the service cycle treated water source comprising softened,acidic and low total dissolved solids (TDS) water, wherein the treatedwater source may be used for washing and/or rinsing in a variety ofcleaning applications; and regenerating the ion exchange resin uponexhaustion using an acid regenerant.

In a still further aspect of the invention, a method for using asoftened acidic water source comprises: contacting an article or surfacein need of cleaning with a treated water source, wherein said treatedwater source is a softened, acidic low total dissolved solids (TDS)water generated by treating a hard water source with at least one ionexchange resin, wherein the ion exchange resin generates a treated watersource by exchanging protons on said resin for dissolved cationsincluding water hardness ions and total dissolved solids in said watersource, and wherein said ion exchange resin is regenerated using anacid.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B show an embodiment of an apparatus that can be retrofittedto a system for use of an acid regenerating ion exchange resin invarious cleaning applications.

FIG. 2 shows an embodiment of the apparatus that uses an acid regenerantto regenerate an ion exchange resin according to the invention.

FIGS. 3A-3B show an embodiment of the invention using a layered ionexchange resin bed (3A) and a mixed layered ion exchange resin bed (3B)for treating a water source.

FIG. 4 shows an embodiment of the invention of a retrofitted ware washsystem using an acid regenerating ion exchange resin apparatus togenerate acidified water for use in a cleaning application.

FIG. 5 shows an embodiment of the invention of FIG. 4 further employingan additional water treatment apparatus with the acid regenerating ionexchange resin apparatus.

FIG. 6 shows a diagram of the capacity of an acid regenerated ionexchange resin v. pH of treated water according to an embodiment of theinvention.

FIG. 7 shows a diagram of the capacity of an acid regenerated ionexchange resin v. water hardness of treated water according to anembodiment of the invention.

FIG. 8 shows a diagram of the capacity of a layered weak acid ionexchange resin bed (single type of resin) v. a layered weak acid ionexchange resin and strong acid ion exchange resin bed on treatment ofwater hardness.

FIG. 9 shows a diagram of the pH v. the capacity (gallons) of a layeredweak acid ion exchange resin bed (single type of resin) v. a layeredweak acid ion exchange resin and strong acid ion exchange resin bed.

FIGS. 10A-10B show diagrams of the pH achieved from the acid resinsresulting from the regeneration using a strong acid regenerant accordingto an embodiment of the invention.

FIG. 11 shows a diagram of the hardness of treated water after theregeneration of the resin employing the exemplary acid regenerants ofFIGS. 10A-10B according to an embodiment of the invention.

FIG. 12 shows a diagram of the pH of the resin employing varioussuitable acid regenerants according to embodiments of the invention.

FIG. 13 shows a diagram of the hardness of treated water after theregeneration of the resin employing the various suitable acidregenerants of FIG. 12 according to embodiments of the invention.

Various embodiments of the present invention will be described in detailwith reference to the drawings, wherein like reference numeralsrepresent like parts throughout the several views. Reference to variousembodiments does not limit the scope of the invention. Figuresrepresented herein are not limitations to the various embodimentsaccording to the invention and are presented for exemplary illustrationof the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure relates to methods and systems for using acidregenerate-able ion exchange resins at a point of use (i.e.non-integrated systems) to pre-treat water for various cleaningapplications, including institutional and industrial applications. Themethods and systems or apparatuses for obtaining and applying softenedacidic water herein have many advantages over conventional watersoftening systems and/or apparatuses aimed at reducing water hardness.For example, the invention provides numerous unexpected downstreambenefits, including for example, improving water quality and cleaningresults, reducing consumption of detergents, other polymers and/orcleaning components in various cleaning applications, and preventingscale buildup, spotting and/or filming on treated surfaces. In addition,there are various advantages of the methods, systems and apparatusesusing acid softened water generated at a point of use according to theinvention to initiate downstream events in a cleaning application,including for example the regeneration of the resin and/or dispensing ofadditional cleaning components in a system.

The embodiments of this invention are not limited to particular methods,systems and apparatuses for obtaining softened acidic water at a pointof use and applying softened acidic water to a particular cleaningapplication, which can vary and are understood by skilled artisans. Itis further to be understood that all terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting in any manner or scope. For example, as used in thisspecification and the appended claims, the singular forms “a,” “an” and“the” can include plural referents unless the content clearly indicatesotherwise. Further, all units, prefixes, and symbols may be denoted inits SI accepted form. Numeric ranges recited within the specificationare inclusive of the numbers defining the range and include each integerwithin the defined range.

DEFINITIONS

So that the present invention may be more readily understood, certainterms are first defined. Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which embodiments ofthe invention pertain. Many methods and materials similar, modified, orequivalent to those described herein can be used in the practice of theembodiments of the present invention without undue experimentation, thepreferred materials and methods are described herein. In describing andclaiming the embodiments of the present invention, the followingterminology will be used in accordance with the definitions set outbelow.

The term “about,” as used herein, refers to variation in the numericalquantity that can occur, for example, through typical measuring andliquid handling procedures used for making concentrates or use solutionsin the real world; through inadvertent error in these procedures;through differences in the manufacture, source, or purity of theingredients used to make the compositions or carry out the methods; andthe like. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities.

As used herein, the terms “builder,” “chelating agent,” and“sequestrant” refer to a compound that forms a complex (soluble or not)with water hardness ions (from the wash water, soil and substrates beingwashed) in a specific molar ratio. Chelating agents that can form awater soluble complex include sodium tripolyphosphate, EDTA, DTPA, NTA,citrate, and the like. Sequestrants that can form an insoluble complexinclude sodium triphosphate, zeolite A, and the like. As used herein,the terms “builder,” “chelating agent “and” sequestrant” are synonymous.

As used herein, the term “lacking an effective amount of chelating (orbuilder/sequestrant) agent” refers to a composition, mixture, oringredients that contains too little chelating agent, builder, orsequestrant to measurably affect the hardness of water.

The term “cleaning,” as used herein, means to perform or aid in soilremoval, bleaching, microbial population reduction, or combinationthereof.

As used herein, the term “disinfectant” refers to an agent that killsall vegetative cells including most recognized pathogenicmicroorganisms, using the procedure described in A.O.A.C. Use DilutionMethods, Official Methods of Analysis of the Association of OfficialAnalytical Chemists, paragraph 955.14 and applicable sections, 15thEdition, 1990 (EPA Guideline 91-2). As used herein, the term “high leveldisinfection” or “high level disinfectant” refers to a compound orcomposition that kills substantially all organisms, except high levelsof bacterial spores, and is effected with a chemical germicide clearedfor marketing as a sterilant by the Food and Drug Administration. Asused herein, the term “intermediate-level disinfection” or “intermediatelevel disinfectant” refers to a compound or composition that killsmycobacteria, most viruses, and bacteria with a chemical germicideregistered as a tuberculocide by the Environmental Protection Agency(EPA). As used herein, the term “low-level disinfection” or “low leveldisinfectant” refers to a compound or composition that kills someviruses and bacteria with a chemical germicide registered as a hospitaldisinfectant by the EPA.

As used herein, the phrase “food processing surface” refers to a surfaceof a tool, a machine, equipment, a structure, a building, or the likethat is employed as part of a food processing, preparation, or storageactivity. Examples of food processing surfaces include surfaces of foodprocessing or preparation equipment (e.g., slicing, canning, ortransport equipment, including flumes), of food processing wares (e.g.,utensils, dishware, wash ware, and bar glasses), and of floors, walls,or fixtures of structures in which food processing occurs. Foodprocessing surfaces are found and employed in food anti-spoilage aircirculation systems, aseptic packaging sanitizing, food refrigerationand cooler cleaners and sanitizers, ware washing sanitizing, blanchercleaning and sanitizing, food packaging materials, cutting boardadditives, third-sink sanitizing, beverage chillers and warmers, meatchilling or scalding waters, auto dish sanitizers, sanitizing gels,cooling towers, food processing antimicrobial garment sprays, andnon-to-low-aqueous food preparation lubricants, oils, and rinseadditives.

As used herein, the phrase “food product” includes any food substancethat might require treatment with an antimicrobial agent or compositionand that is edible with or without further preparation. Food productsinclude meat (e.g., red meat and pork), seafood, poultry, produce (e.g.,fruits and vegetables), eggs, living eggs, egg products, ready to eatfood, wheat, seeds, roots, tubers, leafs, stems, corns, flowers,sprouts, seasonings, or a combination thereof. The term “produce” refersto food products such as fruits and vegetables and plants orplant-derived materials that are typically sold uncooked and, often,unpackaged, and that can sometimes be eaten raw.

As used herein, the phrase “health care surface” refers to a surface ofan instrument, a device, a cart, a cage, furniture, a structure, abuilding, or the like that is employed as part of a health careactivity. Examples of health care surfaces include surfaces of medicalor dental instruments, of medical or dental devices, of electronicapparatus employed for monitoring patient health, and of floors, walls,or fixtures of structures in which health care occurs. Health caresurfaces are found in hospital, surgical, infirmity, birthing, mortuary,and clinical diagnosis rooms. These surfaces can be those typified as“hard surfaces” (such as walls, floors, bed-pans, etc.), or fabricsurfaces, e.g., knit, woven, and non-woven surfaces (such as surgicalgarments, draperies, bed linens, bandages, etc.), or patient-careequipment (such as respirators, diagnostic equipment, shunts, bodyscopes, wheel chairs, beds, etc.), or surgical and diagnostic equipment.Health care surfaces include articles and surfaces employed in animalhealth care.

As used herein, the term “instrument” refers to the various medical ordental instruments or devices that can benefit from cleaning with acomposition according to the present invention. As used herein, thephrases “medical instrument,” “dental instrument,” “medical device,”“dental device,” “medical equipment,” or “dental equipment” refer toinstruments, devices, tools, appliances, apparatus, and equipment usedin medicine or dentistry. Such instruments, devices, and equipment canbe cold sterilized, soaked or washed and then heat sterilized, orotherwise benefit from cleaning in a composition of the presentinvention. These various instruments, devices and equipment include, butare not limited to: diagnostic instruments, trays, pans, holders, racks,forceps, scissors, shears, saws (e.g. bone saws and their blades),hemostats, knives, chisels, rongeurs, files, nippers, drills, drillbits, rasps, burrs, spreaders, breakers, elevators, clamps, needleholders, carriers, clips, hooks, gouges, curettes, retractors,straightener, punches, extractors, scoops, keratomes, spatulas,expressors, trocars, dilators, cages, glassware, tubing, catheters,cannulas, plugs, stents, scopes (e.g., endoscopes, stethoscopes, andarthoscopes) and related equipment, and the like, or combinationsthereof.

As used herein, the term “laundry,” refers to woven and non-wovenfabrics, and textiles. For example, laundry can include, but is notlimited to, clothing, bedding, towels and the like.

As used herein, the term “microorganism” refers to any noncellular orunicellular (including colonial) organism. Microorganisms include allprokaryotes. Microorganisms include bacteria (including cyanobacteria),spores, lichens, fungi, protozoa, virinos, viroids, viruses, phages, andsome algae. As used herein, the term “microbe” is synonymous withmicroorganism.

As used herein, the term “sanitizer” refers to an agent that reduces thenumber of bacterial contaminants to safe levels as judged by publichealth requirements. In an embodiment, sanitizers for use in thisinvention will provide at least a 99.999% reduction (5-log orderreduction). These reductions can be evaluated using a procedure set outin Germicidal and Detergent Sanitizing Action of Disinfectants, OfficialMethods of Analysis of the Association of Official Analytical Chemists,paragraph 960.09 and applicable sections, 15th Edition, 1990 (EPAGuideline 91-2). According to this reference a sanitizer should providea 99.999% reduction (5-log order reduction) within 30 seconds at roomtemperature, 25+/−2° C., against several test organisms.

For the purpose of this patent application, successful microbialreduction is achieved when the microbial populations are reduced by atleast about 50%, or by significantly more than is achieved by a washwith water. Larger reductions in microbial population provide greaterlevels of protection.

Differentiation of antimicrobial “-cidal” or “-static” activity, thedefinitions which describe the degree of efficacy, and the officiallaboratory protocols for measuring this efficacy are considerations forunderstanding the relevance of antimicrobial agents and compositions.Antimicrobial compositions can affect two kinds of microbial celldamage. The first is a lethal, irreversible action resulting in completemicrobial cell destruction or incapacitation. The second type of celldamage is reversible, such that if the organism is rendered free of theagent, it can again multiply. The former is termed microbiocidal and thelater, microbistatic. A sanitizer and a disinfectant are, by definition,agents which provide antimicrobial or microbiocidal activity. Incontrast, a preservative is generally described as an inhibitor ormicrobistatic composition.

As used herein, the term “solubilized water hardness” or “waterhardness” refers to hardness minerals dissolved in ionic form in anaqueous system or source, i.e., Ca⁺⁺ and Mg⁺⁺. Solubilized waterhardness does not refer to hardness ions when they are in a precipitatedstate, i.e., when the solubility limit of the various compounds ofcalcium and magnesium in water is exceeded and those compoundsprecipitate as various salts such as, for example, calcium carbonate andmagnesium carbonate.

As used herein, the term “threshold agent” refers to a compound thatinhibits crystallization of water hardness ions from solution, but thatneed not form a specific complex with the water hardness ion. Thisdistinguishes a threshold agent from a chelating agent or sequestrant.Threshold agents include a polyacrylate, a polymethacrylate, anolefin/maleic copolymer, and the like.

As used herein, the term “ware” refers to items such as eating andcooking utensils, dishes, and other hard surfaces such as showers,sinks, toilets, bathtubs, countertops, windows, mirrors, transportationvehicles, and floors. Wares are often comprised of various types ofplastics including but are not limited to, polycarbonate polymers (PC),acrilonitrile-butadiene-styrene polymers (ABS), and polysulfone polymers(PS). Another exemplary plastic includes polyethylene terephthalate(PET).

As used herein, the term “warewashing” refers to washing, cleaning, orrinsing ware. Ware also refers to items made of plastic.

As used herein, the terms “water” or “water source,” refer to any sourceof water that can be used with the methods, systems and apparatuses ofthe present invention. The embodiments of the invention are particularlysuitable for use of hard (i.e. non-softened) water sources. Exemplarywater sources suitable for use in the present invention include, but arenot limited to, water from a municipal water source, or private watersystem, e.g., a public water supply or a well. The water can be citywater, well water, water supplied by a municipal water system, watersupplied by a private water system, and/or water directly from thesystem or well. The water can also include water from a used waterreservoir, such as a recycle reservoir used for storage of recycledwater, a storage tank, or any combination thereof. In some embodiments,the water source is not an industrial process water, e.g., waterproduced from a bitumen recovery operation. In other embodiments, thewater source is not a waste water stream.

As used herein, the term “water soluble” refers to a compound orcomposition that can be dissolved in water at a concentration of morethan 1 wt-%. As used herein, the terms “slightly soluble” or “slightlywater soluble” refer to a compound or composition that can be dissolvedin water only to a concentration of 0.1 to 1.0 wt-%. As used herein, theterm “substantially water insoluble” or “water insoluble” refers to acompound that can be dissolved in water only to a concentration of lessthan 0.1 wt-%. For example, magnesium oxide is considered to beinsoluble as it has water solubility (wt-%) of about 0.00062 in coldwater, and about 0.00860 in hot water. Other insoluble compounds for usewith the methods of the present invention include, for example:magnesium hydroxide with a water solubility of 0.00090 in cold water and0.00400 in hot water; aragonite with a water solubility of 0.00153 incold water and 0.00190 in hot water; and calcite with a water solubilityof 0.00140 in cold water and 0.00180 in hot water.

The term “weight percent,” “wt-%,” “percent by weight,” “% by weight,”and variations thereof, as used herein, refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent,” “%,” and the like are intended to be synonymous with“weight percent,” “wt-%,” etc.

Embodiments of the Invention

According to an embodiment of the invention methods, systems andapparatuses provide for the use of acid regenerate-able ion exchangeresins to pre-treat water for cleaning applications. Preferably, resinshaving a polymer matrix with carboxylic acid functional groups are usedto capture water hardness ions and thereafter acids are used toregenerate the resin for re-use in generating a softened acidic watersource for use in a cleaning application. Surprisingly, the presentinvention provides for novel uses of the various effluent waters of themethods, systems and apparatuses of the invention. In particular,whereas the effluent from the regeneration step is put to a waste streamand/or the effluent water from a service cycle is acidic softened waterand may be used for washing or rinsing in a variety of cleaningapplications. While an understanding of the mechanism is not necessaryto practice the present invention and while the present invention is notlimited to any particular mechanism of action, it is contemplated that,in some embodiments the benefits afforded according to the inventionresult from the generation of protons from the exchange of waterhardness ions onto the resin.

According to a further embodiment of the invention, the methods, systemsand apparatuses provide novel mechanisms for monitoring water sources.As opposed to monitoring and/or measuring water hardness ions in a watersource, the use of conventional pH measurements can be used to triggervarious events in a cleaning application. For example, a pH measurement(i.e. caused by the increase in protons/acidic water) can be used totrigger the step of regenerating the resin of a water treatmentcomponent or apparatus, and/or varying the detergent consumption neededto wash or rinse a surface in a particular cleaning application.Alternatively, the pH of incoming hard water can be compared to thetreated acidic softened water, wherein the pH differential can be usedto monitor a working system.

The invention overcomes the shortfalls of commercially-available watersoftening methods by providing an improved method for regenerating aresin and providing cleaning benefits from the treated effluent of asystem, namely the protons contributing to cleaning efficacy in variouscleaning applications. In addition, the invention provides theunexpected benefits of requiring the use of reduced amounts of polymers,threshold agents/reagents and/or other components in detergentcompositions. In a further unexpected application, the inventionprovides for the elimination of a chemistry input into a cleaningapplication, such as acidic rinse aids.

One skilled in the art will ascertain additional benefits, uses and/orapplications based upon the disclosure of the methods and systems of thepresent invention disclosed herein. Such embodiments are incorporated inthe scope of the present invention.

Apparatuses and Systems for Water Treatment

In some embodiments the present invention relates to apparatuses and/orsystems employing an acid regenerated ion exchange resin(s). Theapparatuses and/or systems are suitable for use in controlling waterhardness. In some aspects, the apparatuses and/or systems of the presentinvention include a substantially water insoluble resin material.Preferably, apparatuses and/or systems of the present invention do notprecipitate a substance out of the water (e.g. a threshold agent).Without being limited to a particular theory of the invention, theapparatuses and/or systems result in the release of protons from theresin in exchange for binding water hardness ions onto the resin,causing an alteration in pH (i.e. acidic softened water), namely adecrease in pH as a result of the generation of protons from the resin.More preferably, the apparatuses and/or systems do not increase thetotal dissolved solids (TDS) of the water source treated.

In some aspects, the apparatuses and/or systems of the present inventioninclude a water treatment composition or water preparation system(herein after the terms are used synonymously). The water treatmentcomposition may be in a variety of physical forms. In one embodiment thewater treatment composition comprises a ion exchange resin.

Ion Exchange Resins

The ion exchange resin according to the apparatuses and/or systems ofthe invention may be in a variety of physical forms, including forexample, a sheet, a bead, a membrane or the like. In some embodiments,the ion exchange resin is a substantially water insoluble resinmaterial. In some embodiments, the ion exchange resin is an acid cationexchange resin. As disclosed herein, a variety of resin materials may beused with the apparatuses of the present invention to treat a watersource by exchanging protons on the ion exchange resins for dissolvedcations including water hardness ions and total dissolved solids in thewater source.

In some embodiments, the resin material includes an acid cation exchangeresin. The acid cation exchange resin may include a weak acid cationexchange resin, a strong acid cation exchange resin, and/or combinationsthereof (often referred to as layered resin systems or beds, which mayfurther include layered mixed resin systems or beds, as one skilled inthe art appreciates).

In an embodiment the ion exchange resin is a strong acid exchange resinhaving a polystyrene matrix and sulfonic acid functional group. In anadditional embodiment, the ion exchange resin may have a polystyrenewith sulfonic acid functional group, polystyrene with sulfonic acidfunctional group and mixtures of thereof.

Weak acid cation exchange resins suitable for use in the presentinvention include, but are not limited to, a cross-linked acrylic acidwith carboxylic acid functional group, a cross-linked methacrylic acidwith carboxylic acid functional group, and mixtures thereof. In someembodiments, resin polymers have additional copolymers added. Thecopolymers include but are not limited to butadiene, ethylene,propylene, acrylonitrile, styrene, vinylidene chloride, vinyl chloride,and derivatives and mixtures thereof.

In a preferred embodiment the ion exchange resin is a weak acid exchangeresin having a polyacrylic copolymer matrix and a carboxylic acidfunctional group. Preferably the ion exchange resin has a surface withfunctional groups comprising carboxylic acids. Alternatively, the ionexchange resin has a surface comprising functional groups comprisingsulfonic acids.

In some embodiments, the resin material is an acrylic acid polymer thatprovides a polyacrylate material having a molecular weight of about 150to about 100,000 to the water source. In other embodiments, the resinmaterial provides a polyacrylate material having a relatively lowmolecular weight, such as a molecular weight less than about 20,000, tothe water source. Without being limited according to the invention, allranges of molecular weights recited are inclusive of the numbersdefining the range and include each integer within the defined range.

In some embodiments, the resin includes a weak acid cation exchangeresin having H+ ions attached to the active sites. In additionalembodiments, the resin includes a weak acid cation exchange resin havingcarboxylic acid functional groups attached to the active sites.

Various commercially available weak acid cation exchange resins areavailable, and include but are not limited to: Amberlite® IRC 76 (DowChemical Company); Dowex® MAC-3 (Dow Chemical Company); and a variety ofadditional resins. Additional description of suitable resin materialsand systems, including additional commercially available resins aredisclosed in U.S. patent application Ser. No. 12/764,621, entitled“Methods and Apparatus for Controlling Water Hardness,” the entirecontents of which are hereby expressly incorporated herein by reference.

An alternative embodiment of the invention is the use of an anionexchange resin. Without wishing to be bound to a particular theory ofthe invention, use of an anion exchange resin may provide benefitsthrough obtaining a softened alkaline water source.

As one skilled in the art will ascertain, the resin material may beprovided in any shape and size, including beads, rods, disks orcombinations of more than one shape. In some embodiments, the resinmaterial is selected from the group consisting of a gel type resinstructure, a macroporous type resin structure, and combinations thereof.Without wishing to be bound by any particular theory it is thought thatthe resin particle size may affect the ability of the resin material tocontrol water hardness. For example, in some embodiments, the resinmaterial may have a particle size of from about 0.5 mm to about 1.6 mm.In other embodiments, the resin material may have a particle size aslarge of 5.0 mm. The resin material may also include a mixture ofparticle sizes, viz. a mixture of large and small particles. Withoutbeing limited according to the invention, all ranges recited areinclusive of the numbers defining the range and include each integerwithin the defined range.

Additional factors that are thought to have an effect on the ability ofthe resin material to control water hardness include, but are notlimited to, the particle size distribution, the amount of cross linking,and the polymers used. In some embodiments, the cross-linked polymer(e.g. acrylic acid) is about 0.5% cross-linked to about 25%cross-linked. In other embodiments, the polymer is less than about 8%cross-linked, less than about 4% cross-linked, or less than about 2%cross-linked. Without being limited according to the invention, allranges recited are inclusive of the numbers defining the range andinclude each integer within the defined range.

In some embodiments, the ability of the resin material to control waterhardness is impacted by whether there is a narrow particle sizedistribution, e.g., a uniformity coefficient of 1.2 or less, or a wide(Gaussian) particle size distribution, e.g., a uniformity coefficient of1.5 to 1.9. Without being limited according to the invention, all rangesrecited are inclusive of the numbers defining the range and include eachinteger within the defined range.

Further, it is thought that the selectivity of the resin can be modifiedto tailor the resin to have an affinity for one ion over another. Forexample, the amount of cross linking and type of polymers included inthe resin are thought to impact the selectivity of the resin. Aselective affinity for particular ions over other ions may be beneficialin situations where a high affinity for certain ions, e.g., copper, maybe damaging, e.g., foul or poison, to the resin itself. The resinmaterial may bind cations by a variety of mechanisms including, but notlimited to, by ionic or electrostatic force.

Acid Regenerants

Acid regenerants suitable for use in the regeneration of the ionexchange resins according to the apparatuses and/or systems of theinvention are necessary to remove water hardness ions from the resins. Avariety of acid regenerants may be employed to provide protons to theresin to restore capacity to soften and acidify water in need oftreatment according to the invention. In an aspect, the regenerant is anacid. Exemplary acids according to the invention include hydrochloricacid, sulfuric acid, phosphoric acid, nitric acid, citric acid, aceticacid, methane sulfonic acid and methyl sulfonic acid. In some aspectsthe acid regenerant is a strong acid. In other aspects the acidregenerant is a weak acid. In an additional aspect, the acid regenerantmay be an inorganic and/or organic acid. In an additional aspect, theregenerant is an acid salt. Exemplary acid salts include urea sulfateand monosodium sulfuric acid. In a preferred aspect, the regenerant isurea sulfate.

In an aspect, the acid regenerant is housed in a storage reservoir in aconcentrated form that is commercially-available. Concentratespreferably have pH less than about 5, preferably less than about 2,preferably less than about 1, and more preferably less than about 0.Without being limited according to the invention, all pH ranges recitedare inclusive of the numbers defining the range and include each integerwithin the defined range. For example, concentrated urea sulfate havinga pH from about −3 to about 1 is employed as a concentrated acidregenerant for the ion exchange resins of the invention.

Preferably, the acid regenerant is be diluted prior to passing over theion exchange resin. This allows for the use of concentrated acidregenerants, which among other benefits reduces the transportationburdens and costs. In an aspect, the dilution ratio of acid regenerantto diluent (e.g. water) is from about 1:1 to about 1:20, preferably fromabout 1:2 to about 1:20. Without being limited according to theinvention, all dilution ratio ranges recited are inclusive of thenumbers defining the range and include each integer within the definedrange.

In an aspect, the acid regenerant is in contact with the resin for aperiod of time from a few minutes to about 90 minutes, preferably fromabout one minute to about 60 minutes, and more preferably from about 5minutes to about 30 minutes.

In an aspect of the invention, the concentration of the acid regenerantused in the regeneration cycle will depend upon the type of acidregenerant employed. In some embodiments, the concentration of the acidused in a solution for providing the acid regenerant to the ion exchangeresin is from about 1% to about 20%, from about 2% to about 10%, orabout 5% to about 10% of access of acid for regeneration. Without beinglimited according to the invention, all ranges recited are inclusive ofthe numbers defining the range and include each integer within thedefined range. In addition, the amount of hardness in need of removalfrom the ion exchange resin will impact the amount of acid regenerantemployed for the regeneration step of the invention.

Exemplary Water Preparation Systems

The apparatuses and/or systems of the present invention may be housedwithin a variety of water preparation systems, to provide point of usegeneration of acidified water for cleaning applications. The apparatusesand/or systems may be retrofitted to a variety of cleaning systems.Cleaning systems may include for example ware wash applications and anyother cleaning system suitable for employing a softened acidic watersource, including those of the invention exhibiting relatively lowertotal dissolved solids (TDS). Such additional cleaning systems mayinclude for example, ware washing and/or sanitizing systems, laundryapplications, hard surface and/or instrument cleaning, bottle washing,clean in place applications, and the like. In addition to cleaningsystems suitable for application of the retrofitted systems of theinvention, any dilution systems employing the treated softened acidicwater source according to the invention are included within the scope ofthe present invention. These may include, for example, aspirators, pumpsfor delivering the treated water source and/or any other dilution systemthat is employed to deliver chemistry and/or a water source to a system.

An example of a water preparation system or apparatus 20 for use in thepresent invention is shown in FIGS. 1A-1B, which may comprise, consistof and/or consist essentially of: an inlet 22 for providing a watersource to a treatment reservoir 26; a treatment reservoir including awater treatment composition 28 (e.g. ion exchange resin) and the watersource to be treated 29; an outlet 24 for providing treated acidic water31 from the treatment reservoir 26; and a treated water delivery line 30for incorporation of the treated acid water into a cleaning application,storage (e.g. reservoir) and/or shipment 32, 34, 36, respectively.

According to the various methods of the invention, the water source 29passes over the ion exchange resin 28, and water hardness cations fromthe water source 29 (e.g. calcium and magnesium ions) attach to the ionexchange resin 28, displacing protons into the treated water sourcecreating an acidic softened water 31.

The apparatuses and/or systems of the present invention are designed forregeneration using an acid regenerant. Once the ion exchange resin 28reaches a point of exhaustion (wherein the multivalent hardness cationsfrom the water source have loaded onto the resin such that insufficientor no further exchange of cations occurs), an acid regenerant is used toremove the multivalent hardness cations from the cation exchange resin.An exemplary embodiment of such regeneration is shown in FIG. 2, whereinthe water preparation system or apparatus 20 further comprises, consistsof and/or consists essentially of a housing or storage reservoir 42containing an acid source 44 and a delivery line 46 for providing theacid source 44 to the treatment reservoir 26. The delivery line 46connects the acid source 44 with a water source 47 to generate a moredilute acid source 48 to regenerate the ion exchange resin 28. Thediluted acid source 48 is then pumped into the treatment reservoir 26 topass over the ion exchange resin 28 and cause the displacement of waterhardness cations with the protons from the dilute acid source, therebyregenerating the exhausted ion exchange resin and generating a wastesource of water containing hardness ions 50 to be removed from the waterpreparation system or apparatus 20.

The regeneration of the ion exchange resins can be triggered by avariety of events, as set forth in the description of the invention. Inan embodiment, the concentrated acid source 44 from the storagereservoir 42 is combined with the water source due to atmosphericpressure within the system triggered by an event. Triggering events, asreferred to herein for the regeneration of the ion exchange resins caninclude, for example, scheduled regeneration cycles based upon eitherset amounts (i.e. threshold levels) of the following and/or measurementsand targeted amounts of the following, including for example, volume ofwater treated by an ion exchange resin, TDS levels in the treated waterand/or water source to be treated according to the invention, pH of thetreated water, number of cleaning events/cycles since the previousregeneration of the ion exchange resin, and the like.

As depicted in FIG. 2, the regeneration step moves the liquids in theopposite direction through the inlets and outlets, 22 and 24respectively, as that described with respect to FIGS. 1A-1B when the ionexchange resin 28 is used to remove water hardness to generate thesoftened acidified water. Beneficially, this reduces the complexity ofthe water preparation system or apparatus 20 in minimizing the number ofinlets/outlets and delivery line. In an additional embodiment, the wasteproduct from the regeneration step (i.e. water containing hardness ions50) could be added to the water source 29 for subsequent treatmentaccording to the methods of the invention.

The apparatuses and/or systems of the present invention may furtheremploy layered resin beds and/or layered mixed resin beds, as shown inFIGS. 3A-3B, respectively. In an embodiment of the invention, a layeredresin bed includes more than one acid cation exchange resin. Forexample, as shown in FIG. 3A, the water preparation system or apparatus20 may comprise, consist of and/or consist essentially of: a first inlet22 for providing a water source to a first treatment reservoir 26(housing a first ion exchange resin 28); a first outlet 24 for providingthe treated acidic water from the first treatment reservoir 26 to asecond treatment reservoir 26; a second inlet 22 for providing thetreated water source to the second treatment reservoir 26 (housing thesecond ion exchange resin 28); and a second outlet for providing thetreated acidic water to a treated water delivery line 30. It is to beunderstood from the description of the invention that a plurality ofresin beds may be employed, e.g. more than two treatment reservoir 26and more than two ion exchange resins 28. As set forth with respect toFIG. 1B, various embodiments of the invention may be employed for thedelivery of the treated acid water into a cleaning application, storage(e.g. reservoir) and/or shipment 32, 34, 36.

In a further embodiment, as shown in FIG. 3B, the water preparationsystem or apparatus 20 may include a layered mixed resin bed which maycomprise, consist of and/or consist essentially of: a first inlet 22 forproviding a water source to a first treatment reservoir 26 (housing afirst ion exchange resin 28); a first outlet 24 for providing thetreated acidic water from the first treatment reservoir 26 to a secondtreatment reservoir 26; a second inlet 22 for providing the treatedwater source to the second treatment reservoir 26 (housing the secondion exchange resin 28, wherein the second ion exchange resin is adifferent ion exchange resin from that housed in the first treatmentreservoir or wherein the second ion exchange resin contains more thanone type of ion exchange resin, one of which may be the same as the ionexchange resin housed in the first treatment reservoir); and a secondoutlet for providing the treated acidic water to a treated waterdelivery line 30.

The layered acid cation exchange resins depicted in FIGS. 3A-3B mayinclude combinations of weak acid cation exchange resins, strong acidcation exchange resins, and/or combinations of both weak acid cationexchange resins and strong acid cation exchange resins.

In some embodiments, the treated water delivery line 30 of a waterpreparation system or apparatus 20 provides treated water 31 to aselected washing and/or cleaning system 32, as shown in FIG. 4. As shownin the illustrated embodiment, the treated water delivery line isconnected to a ware wash machine as source of treated water for thedepicted cleaning application. As set forth according to the invention,the treated water delivery line may be connected to a variety ofadditional cleaning applications, including for example, Ware washing,including for example, automatic ware washing machine, a vehicle washingsystem, an instrument washer, a clean in place system, a food processingcleaning system, a bottle washer, etc.; laundry applications, includingfor example, automatic laundry/textile washing machines; industrial anddomestic applications; and hard surface cleaning applications, includingfor example, clean-in-place systems (CIP), clean-out-of-place systems(COP), automatic bottle washers, washer-decontaminators, sterilizers,ultra and nano-filtration systems, indoor air filters, etc.

In other embodiments, the treated water delivery line 30 provides thetreated acidic water 31 to an additional water treatment apparatus 38,as shown in FIG. 5. The additional water treatment apparatus 38 mayinclude for example, a carbon filter or a reverse osmosis filter.Thereafter the treated water may again be provided as a source for acleaning application, stored (e.g. reservoir) and/or shipped to analternative point of use (e.g. 32, 34, 36). The water that was treatedwith the additional water treatment apparatus 38 may then be connectedby a second water delivery line 40 to the cleaning application, stored(e.g. reservoir) and/or shipped to an alternative point of use (e.g. 32,34, 36). One skilled in the art shall ascertain that one or moreadditional water treatment apparatuses may be employed with the waterpreparation system or apparatus 20 of the invention. In addition, theone or more additional water treatment apparatuses may be employedbefore or after the water source is treated according to the methods ofthe invention with the water preparation system or apparatus 20. Assuch, the configuration of the water preparation system or apparatus 20shown in FIG. 5 treating a water source with the ion exchange resin 28prior to use of the additional water treatment apparatus 38 is anon-limiting embodiment of the invention. In a still further alternativeembodiment, no additional water treatment apparatuses are employed withthe water preparation system or apparatus 20 of the invention.

In some embodiments, there is no filter between the outlet and thetreated water delivery line. In other embodiments, there is a filterbetween the outlet and the treated water delivery line. In addition, aflow control device 40 such as a valve or other mechanism forcontrolling the flow or pressure of the liquids disposed therein fortransport can be provided in the treated water delivery line 30 tocontrol the flow of the treated water 31 into the selected end usedevice, e.g., a washing system, or another water treatment device 32,such as shown in FIG. 1B. In an alternative embodiment, the flow rate ofboth the water source and/or treated water can be controlled by flowcontrol devices. In some embodiments, the water treatment reservoir 26is any reservoir capable of holding the water treatment composition(e.g. ion exchange resin) 28. The reservoir 26 can be for example, atank, a cartridge, a filter bed of various physical shapes or sizes, ora column. In other embodiments, the resin material may be attached oradhered to a solid substrate. The substrate can include, but is notlimited to, a flow-through filter type pad, or paper. The substrate canalso be a particulate that can be fluidized.

The apparatuses and/or systems of the present invention can include oneor more water treatment reservoirs 26. For example, two, three or fourtreatment reservoirs containing the same or different water treatmentcompositions 28 can be used. The one or more treatment reservoirs can beprovided in any arrangement, for example, they may be provided inseries, or in parallel. In some further embodiments, the entiretreatment reservoir can be removable and replaceable. In otherembodiments, the treatment reservoir can be configured such that watertreatment composition contained within the treatment reservoir isremovable and replaceable.

The treatment reservoir may include an inlet for providing water to thetreatment reservoir and an outlet for providing treated water to adesired end use location, e.g., a washing device or another watertreatment device. In some embodiments, the inlet is located at the topof the reservoir, and the outlet is located at the bottom of thereservoir, such as shown in FIG. 3. In alternative embodiments, theinlet is located at the bottom of the reservoir, and the outlet islocated at the top of the reservoir. This allows for the water to flowup through the water treatment composition contained within thetreatment reservoir. In still further embodiments, the inlet and outletmay be located at the top of the reservoir, such as shown in FIGS. 1-2.However, as one skilled in the art will ascertain, the layout and/ordesign of a treatment reservoir and/or the placement and orientation ofthe treatment reservoir within the water preparation system or apparatuswill vary and may be customized to a particular institutional orindustrial application for use.

In some embodiments, the treatment reservoir includes an agitated bed ofthe water treatment composition. Methods for agitating the compositioninclude, for example, flow of water through a column, by fluidization,mechanical agitation, air sparge, educator flow, baffles, flowobstructers, static mixers, high flow backwash, recirculation, andcombinations thereof. The treatment reservoir can further include a headspace above the composition contained therein, in order to allow for amore fluidized bed. In some embodiments, the resin material has adensity slightly higher than the density of water to maximizefluidization and/or agitation of the resin material.

In some embodiments, the inlet can further include a pressurized spraynozzle or educator nozzle. The spray nozzle can provide the water at anincreased force to the treatment reservoir. This increased pressurizedforce can increase the agitation of the water treatment composition andcan circulate the resin through the educator nozzle. In someembodiments, the spray nozzle provides the water to the treatmentreservoir at a rate of about 5 feet per minute to about 200 feet permin.

As disclosed herein, the treatment reservoirs housing the resinsemployed according to the invention may vary in its set-up, orientation,shape and/or size while maintaining the functionality disclosed hereinfor the treatment of water to provide a softened, acidic water source.For example, in an aspect of the invention a longer or narrower housingmay be employed for the treatment reservoirs and/or resins to maximizeor increase the contact time of the water source with the resin systems.In another aspect of the invention, the treatment reservoirs and/orresins may be shorter in length and/or wider to have a relativelyshorter contact time between the water source and the resin systemand/or to maximize flow rate and/or pressure drop within the system.According to an aspect of the invention, the shape and size of thehousing for the treatment reservoirs and/or resins is adjustable and/orcan be modified in order to balance the amount of time a water source isin contact with the cation exchange resin. As one skilled in the artshall appreciate based on the disclosure of the invention, such contacttime between the water source and the exchange resin will further impactthe characteristics of the treated acidified water source, such as theextent of acidification of the water, amount of TDS and/or extent ofremoval of hardness ions.

Additional Functional Groups

In some embodiments, an additional functional ingredient may be includedin the water preparation systems along with the water treatmentcomposition (e.g. ion exchange resin) housed within a treatmentreservoir. The additional functional ingredients can be included withinthe treatment reservoir and/or water treatment composition, or they canbe provided to the treatment reservoir from an external source, e.g., anadditional functional ingredient inlet.

Additional functional ingredients can be added directly to the watersource to be treated prior to the water source entering the treatmentapparatus. Alternatively, the additional ingredient can be added to thetreatment reservoir prior to the water source being passed through theion exchange resin.

Additional functional ingredients suitable for use with the apparatusesand/or systems of the present invention include any materials thatimpart beneficial properties to the water treatment methods, the watersource being treated, or any combination thereof. Examples of suitableadditional functional ingredients include surfactants, preferablysurfactants exhibiting wetting properties (e.g. rinse additives toincrease sheeting), sanitizing agents and/or sterilizing agents (e.g.providing sanitizing rinse), acidic detergents, enzymatic detergents andthe like.

Methods of Treating a Water Source According to the Invention

In some aspects, the present invention provides methods for controllingwater hardness and producing an acidic softened water source. An acidicsoftened water having a hardness of less than about 2 grains and havinga pH less than about 7, more preferably less than about 6, is producedaccording to the methods of the invention. Thereafter the acidicsoftened water can be employed for a variety of cleaning applications,whether at a point of use or stored for such use at a later time and/orpoint of use.

The methods directed to controlling water hardness are also understoodto include methods for reducing scaling, buildup and/or soiling ontreated surfaces wherein the acidic softened water according to theinvention is applied. In addition, the methods of the present inventionare further understood to include the protecting of equipment, e.g.,industrial equipment, from the same scale build up and/or soiling andprovide increased cleaning efficacy through the application of thesoftened acidic water to a surface in need of treatment. Each of thesame methods are also effective in reducing the use of conventionaldetersive compositions as a result of the acidic softened water; and/orreducing the need for specific chemistries, e.g., those containingthreshold agents, chelating agents, or sequestrants, or phosphorous, indownstream cleaning processes.

The methods as disclosed herein may include contacting a water treatmentcomposition (e.g. acid regenerated resin material) with a water source,namely a hard water source. In some embodiments, the water treatmentcomposition is contained within a treatment reservoir and/or a waterpreparation system. The step of contacting can include, but is notlimited to, running the water source over or through the water treatmentcomposition (e.g. ion exchange resin). As one skilled in the art willascertain, the contact time for the water source is dependent on avariety of factors, including, for example, the pH of the water source,the hardness of the water source, and the temperature of the watersource.

A water source may be applied (i.e. water source contacted with theresin) at a variety of flow rates, as one of skill in the art can applywithout undue experimentation. For example, in preferred embodiments theflow rate through the systems of the invention is from about 0.5 toabout 50 gallons per minute. In other embodiments the flow rate is lessthan about 8 gallons per minute, less than about 40 gallons per minute,less than about 100 gallons per minute, less than about 200 gallons perminute, or from about 100 to about 1500 gallons per minute, from about160 to about 1400 gallons per minute, or about 400 to about 1200 gallonsper minute. For further example, in some embodiments, the apparatuses ofthe present invention have a flow through rate of about less than about1 cubic feet per minute, less than about 5 to about 200 cubic feet perminute, about 20 to about 175 cubic feet per minute, or about 50 toabout 150 cubic feet per minute. Without being limited according to theinvention, all flow rate ranges recited are inclusive of the numbersdefining the range and include each integer within the defined range.

For further example, a conventional ion exchange device is designed fora flow rate of about 0.3 to about 3.0 feet per minute of water velocity.This flow rate is important to allow time for the diffusion of ions tothe surface of the resin from the water for the ion exchange process tooccur. Without being limited according to the invention, all flow ratesranges recited are inclusive of the numbers defining the range andinclude each integer within the defined range.

Optionally, in some embodiments, the method includes heating the watersource prior to the step of contacting the water treatment composition(e.g. resin). Any means of heating the water source may be used with themethods and apparatuses of the present invention. In some embodiments,the water is heated to a temperature of about 30° C. to about 100° C.All temperature ranges recited are inclusive of the numbers defining therange and include each integer within the defined range.

In some aspects the water treatment according to the invention providesa cold, hard water source to a water preparation system. Aftercontacting the water source with the water treatment composition (e.g.resin) and heating, a treated, soft, acidic water is obtained and may beapplied to the various applications of use disclosed herein. Althoughnot intending to be bound to any particular theory of the invention,protons from the resin (e.g. H⁺ from the carboxylic acid group on theweak acid ion exchange resin) are exchanged with water hardness ions inthe water source to provide the treated, soft, acidic water.

Preferably the controlling of water hardness and producing an acidicsoftened water source according to the invention result in a treatedwater source having a pH less than about 7, more preferably less thanabout 6. Without being limited according to the invention, all pH rangesrecited are inclusive of the numbers defining the range and include eachinteger within the defined range.

The treated water source preferably has a water hardness less than about3 grains, more preferably less than about 2 grains, more preferably lessthan about 1 grain, and still more preferably about 0 grains. Withoutbeing limited according to the invention, all ranges of water hardnessrecited are inclusive of the numbers defining the range and include eachinteger within the defined range.

According to the methods of the invention the resin of the watertreatment composition may be contacted with the water source until apoint of exhaustion, viz. loaded with a plurality of multivalenthardness cations as a result of having a sufficient amount of watersource run over it. In some embodiments, the plurality of multivalentcations includes, but is not limited to, the calcium and magnesiumpresent in the water source. Without wishing to be bound by anyparticular theory, it is thought that as the water runs over the resin,the calcium and magnesium ions in the water will attach to the resin,displacing protons into the treated water source creating an acidicsoftened water.

At the point the resin is exhausted, e.g. can no longer exchange protonswith the water hardness ions of the water source, the resin isregenerated according to the methods disclosed herein. According to theinvention, the ion exchange resin is regenerated using an acid, namelyan acid regenerant. According to the invention, the acid regenerantprovides protons to the resin to restore capacity to soften and acidifywater in need of treatment according to the invention. In an aspect, theacid regenerant is a strong mineral acid or an acid salt. A preferredembodiment for regenerating the ion exchange resin uses urea sulfate asthe acid regenerant.

The contacting of the exhausted resin with the acid regenerant may befrom a few minutes to about 90 minutes, preferably from about one minuteto about 60 minutes, and more preferably from about 5 minutes to about30 minutes. Without being limited according to the invention, all rangesare inclusive of the numbers defining the range and include each integerwithin the defined range.

According to the methods of the invention, the effluent water in theregeneration step may be disposed of in a waste stream. However,thereafter, the effluent water (e.g. treated water) in the normalservice cycle is again acidic softened water and can be used accordingto the various methods disclosed herein.

The regeneration of the resins according to the invention may occurbased on measurements obtained from the apparatus and/or systems of theinvention. In an alternative embodiment, regeneration of the resinsaccording to the invention may occur based on the lapse of a measuredamount of time and/or volume of water treated.

Methods to Trigger Events Using the Acidic Softened Water

The methods, apparatuses and/or systems of the invention may be used fora variety of purposes. For example, the generation of the acidicsoftened water according to the invention may be used to triggerdifferent events in a water preparation system or other apparatus orsystem. In particular, the protons generated from the exchange ofhardness ions onto the resin may be monitored or measured to triggerdifferent events in the water preparation system, other apparatusesand/or systems according to the invention.

The measurements and/or monitoring according to the invention aredistinct from various commercial sensors for detecting changes and/ormeasuring water hardness in a system. For example, U.S. Pat. No.7,651,663 entitled, “Appliance Using a Water Hardness Sensor System andMethod of Operating the Same”, incorporated herein by reference in itsentirety, measures water hardness according to the amount of hardnessions (e.g. Ca²⁺, Mg²⁺) in a water source. According to the invention,the methods, apparatuses and/or systems do not measure water hardness.As opposed to these types of calorimetric or fluorescent assaysmeasuring the concentrations of ions such as calcium and magnesium, thepresent invention measures the output and/or effluent from a watertreatment system, measuring the proton released from the ion exchangeresin.

In some aspects, the monitoring or measuring of the protons is achievedby conventional pH measurements measurement of the output from the waterpreparation system or other apparatuses or systems of the invention.Sensors can be used to measure the pH as one example of a suitablemeasuring device. According to additional embodiments, the monitoring ormeasuring device to measure the pH can be employed through the use ofelectrodes, reference electrodes and/or solid state devices to sense pH.For example a pH measurement loop can be employed, such as a pH sensor,including a measuring electrode, a reference electrode and a sensor, apreamplifier and an analyzer or transmitter. Each of these are examplesof suitable measuring devices according to the invention.

In additional aspects, the pH of an incoming (e.g. non-treated) watersource containing hardness ions can be compared to the treated acidicsoftened water exiting the water preparation system, other apparatusesand/or system according to the invention. In such an embodiment, the pHdifferential can be used for a variety of purposes, including monitoringa working system. In an embodiment, the measuring of pH differentialwould detect a decrease in pH differential, triggering an applicableevent, such as regeneration of the ion exchange resin, adding detergentand/or rinse additives or other cleaning agents to be used with thetreated water. Measuring the pH differential is often useful as a resultof the variability of water hardness depending upon a water sourceemployed, as it is well known that hardness levels in influent watersare not constant. Therefore, as a result of methods of the inventionemploying the measurement of pH differential, variations in waterhardness will not be detrimental to a use application as a result of theapparatuses and/or systems being able to monitor and adjust for suchdifferential (e.g. through the triggering of various events as disclosedherein).

The regeneration of the ion exchange resins disclosed herein can betriggered by a variety of events and/or measurements as disclosedherein. In an aspect, the regeneration of the ion exchange resin may betriggered by the measurement of TDS in a system, which shall bedependent on the particular water chemistry inputted to the system. Forexample, in an aspect of the invention, the ion exchange resins removefrom about 70% to about 100% TDS from the water source. In a preferredaspect, the ion exchange resins remove from about 80% to about 100% TDS,or from about 90% to about 100% TDS from the water source. Therefore, inthe event the removal of TDS from a treated water source drops belowabout 70%, or about 80%, or about 90%, such measurement in thedifferential of the TDS between the untreated water and the treatedwater source may trigger the regeneration of the ion exchange resins.

In an additional aspect, the regeneration of the ion exchange resins maybe triggered by pH measurement of the water source and/or the treatedwater. For example, the increase in pH of a treated water source aboveabout 7 may trigger the regeneration of the ion exchange resins. Withoutbeing limited to a particular theory of the invention, the ion exchangeresin may be exhausted between a pH of about 4.9 to about 5, thereforewhen the pH of the treated water source increases to about 7, or above 7the ion exchange resin no longer contributes protons from the resin toacidify and soften the water source. Accordingly, the regeneration ofthe ion exchange resin is triggered.

One skilled in the art is knowledgeable of the various means formonitoring and/or measuring the pH according to the methods oftriggering events using the acidic softened water disclosed herein.Therefore, the scope of the invention is not limited according to themethods for monitoring and/or measuring. Conventional measuringtechniques include the use of sensors. Preferably a sensor is configuredto output a signal to a controller. The sensor may include a substrateand a sensing element disposed on the substrate. The sensing element isin contact with the flow of water in the apparatus and/or system;preferably the sensing element in contact with both the flow of incoming(e.g. non-treated) water and effluent (e.g. treated acidic softened)water.

Events triggered according to use of the apparatuses and/or systemsand/or methods according to the invention include, for example:dispensing of detergents, rinse aids and/or other cleaning compositions;varying the detergent consumption needed to wash or rinse a surfaceaccording to the methods of the invention; regeneration of the ionexchange resins; starting and/or stopping the generation of treatedwater disclosed herein, etc. The triggering of events is initiatedthrough the measurement step, thereafter communicating with a controllerto receive a signal. Thereafter, the controller works to trigger thedesired event for an apparatus and/or system according to the invention.

Methods Employing the Acidic Softened Water

The methods, apparatuses and/or systems of the invention may be used fora variety of cleaning applications to employ the acidic softened water.Thus, an apparatus of the present invention can be used to control waterhardness and/or reduce scale formation and/or enhancing cleaningefficiency and/or reduce spotting and filming caused by high TDS watersand/or reduce or eliminate use of additional chemistry streams forcleaning (e.g. polymers, threshold agents, etc.). Unexpectedly,according to the invention, the protons in the acidic softened watercontribute to the performance of the treated water source.

The systems of the present invention and the methods employing the samecan be included as part of any system or appliance which uses a watersource and is in need of water treatment, e.g., acidification and/orsoftening using a water treatment system. In particular, the systems andapparatuses of the present invention can be used with any appliance ordevice which can provide a water source that would benefit fromtreatment using the apparatuses of the present invention, includingeither or both of acidification and/or softening.

In some aspects, the present disclosure includes methods of using theacidic softened water for low-temperature ware washing and sanitizing.The treated acidic water may be provided to an automatic washing machinefrom the treated water delivery line of the apparatuses and/or systems.The apparatus can be located in a variety of locations relative to thewashing machine. For example, the apparatus may be upstream from thefeed line of the washing machine. Exemplary automatic washing machinessuitable for use with the apparatuses and methods of the presentinvention include, but are not limited to, an automatic ware washingmachine, a vehicle washing system, an instrument washer, a clean inplace system, a food processing cleaning system, a bottle washer, and anautomatic laundry washing machine. Alternatively, the treated water maybe used in a manual washing system. Any automatic washing machine ormanual washing process that would benefit from the use of water treatedin accordance with the methods of the present invention can be used.

In some aspects, the present disclosure includes methods of using theacidic softened water for ware washing applications, including thosedisclosed for example in various ware washing applications using acidformulations, including U.S. Pat. Nos. 8,114,222, 8,092,613, 7,942,980,and 7,415,983, U.S. patent application Ser. Nos. 13/474,771, 13/474,765,13/474,780 and 13/112,412, including all references cited therein, whichare herein incorporated by reference in their entirety. A particularlysuitable application for use of the treated acidic water is for use inan acidic rinse cycle. For example, the treated acidic water may bedispensed with additional acidic compositions through a rinse arm,without or without an additional water rinse step, in order to lower thepH in the final rinse. In an additional application of use, the treatedacidic water may be used in an alternating fashion with alkalinedetergents and steps to improve soil removal.

In some aspects, non-limiting example of dish machines suitable forusing the systems of the invention for water conditioning and/or asource of cleaning and/or rinsing waters are disclosed, for example, inU.S. Pat. No. 9,289,107, entitled Dishmachine, the entire contents ofwhich are hereby expressly incorporated herein by reference. Furtherexamples of dish machines suitable for employing the treated acidicwater disclosed herein, includes, U.S. Pat. Nos. 8,202,373, 8,092,613,7,942,978, 7,871,521, 5,609,174, 4,826,661, 4,690,305, 4,687,121,4,426,362 and in U.S. Pat. Nos. Reissue 32,763 and 32,818, the entirecontents of which are hereby expressly incorporated herein by reference.Some non-limiting examples of dish machines include door machines orhood machines, conveyor machines, undercounter machines, glasswashers,flight machines, pot and pan machines, utensil washers, and consumerdish machines. The dish machines may be either single tank or multi-tankmachines.

A door dish machine, also called a hood dish machine, refers to acommercial dish machine wherein the soiled dishes are placed on a rackand the rack is then moved into the dish machine. Door dish machinesclean one or two racks at a time. In such machines, the rack isstationary and the wash and rinse arms move. A door machine includes twosets arms, a set of wash arms and a rinse arm, or a set of rinse arms.Door machines may be a high temperature or low temperature machine. In ahigh temperature machine the dishes are sanitized by hot water. In a lowtemperature machine the dishes are sanitized by the chemical sanitizer.The door machine may either be a recirculation machine or a dump andfill machine. In a recirculation machine, the detergent solution isreused, or “recirculated” between wash cycles. The concentration of thedetergent solution is adjusted between wash cycles so that an adequateconcentration is maintained. In a dump and fill machine, the washsolution is not reused between wash cycles. New detergent solution isadded before the next wash cycle. Some non-limiting examples of doormachines include the Ecolab Omega HT, the Hobart AM-14, the EcolabES-2000, the Hobart LT-1, the CMA EVA-200, American Dish Service L-3DWand HT-25, the Autochlor A5, the Champion D-HB, and the JacksonTempstar.

The temperature of the cleaning applications in ware wash machinesaccording to the invention may also vary depending on the dish machine,for example if the dish machine is a consumer dish machine or aninstitutional dish machine. The temperature of the cleaning solution ina consumer dish machine is typically about 110° F. (43° C.) to about150° F. (66° C.) with a rinse up to about 160° F. (71° C.). Thetemperature of the cleaning solution in a high temperature institutionaldish machine in the U.S. is about typically about 150° F. (66° C.) toabout 165° F. (74° C.) with a rinse from about 180° F. (82° C.) to about195° F. (91° C.). The temperature in a low temperature institutionaldish machine in the U.S. is typically about 120° F. (49° C.) to about140° F. (60° C.). Low temperature dish machines usually include at leasta thirty second rinse with a sanitizing solution. The temperature in ahigh temperature institutional dish machine in Asia is typically fromabout 131° F. (55° C.) to about 136° F. (58° C.) with a final rinse at180° F. (82° C.).

The disclosed methods of using the acidic softened water may also beused in a pot and pan washer, a utensil washer, glasswashers and/or aconveyor machine. A conveyor machine refers to a commercial dishmachine, wherein the soiled dishes are placed on a rack that movesthrough a dish machine on a conveyor. A conveyor machine continuouslycleans racks of soiled dishes instead of one rack at a time. Here themanifolds are typically stationary or oscillating and the rack movesthrough the machine. A conveyor machine may be a single tank ormulti-tank machine. The conveyor machine may include a prewash section.A conveyor machine may be a high temperature or low temperature machine.Finally, conveyor machines primarily recirculate the detergent solution.Some non-limiting examples of conveyor machines include the EcolabES-4400, the Jackson AJ-100, the Stero SCT-44, and the Hobart C-44, andC-66.

In some embodiments, the dish or ware machine can incorporate an acidregenerate-able ion exchange resin system at a point of use.Beneficially, the use of the acid regenerate-able ion exchange resinsystem at a point of use avoids the need for an extra, external, waterconditioning system. Further benefits result from the use of the systemat a point of use is that the demands on the water within the facilityor location are associated with the particular dish or other machine,instead of the rest of the water used in the facility.

In additional aspects, the present disclosure includes methods of usingthe acidic softened water for laundry applications. For example, theacidic treated water can be used in an automatic textile washing machineat the pre-treatment, washing, souring, softening, and/or rinsingstages. In a particular embodiment, the present invention may be usedwith a washing machine in a variety of ways. In some embodiments, atreatment reservoir housing the ion exchange resin may be connected to alaundry detergent dispensing device. The treatment reservoir may be usedto supply treated water to a washing system and/or to a rinsing systemof a laundry washing machine. In some embodiments, the treatmentreservoir may be used to supply a mixture of treated water and detergentto a laundry washing system.

In still additional aspects, the present disclosure includes methods ofusing the acidic softened water in a variety of additional industrialand domestic applications. For example, according to embodiments of theinvention the acidic softened water can be delivered to a variety ofcleaning applications through the use of dilution systems, which mayinclude for example an aspirator or other pump that feeds into acleaning system.

The water treatment methods and apparatuses can be employed in aresidential setting or in a commercial setting, e.g., in a restaurant,hotel, hospital. In addition to the ware washing (e.g., washing eatingand cooking utensils and dishes) and laundry applications, for example,a water treatment method, system, or apparatus of the present inventioncan be used in: other hard surfaces such as showers, sinks, toilets,bathtubs, countertops, windows, mirrors, and floors; in vehicle careapplications, e.g., to treat water used for pre-rinsing, e.g., analkaline presoak and/or low pH presoak, washing, polishing, and rinsinga vehicle; industrial applications, e.g., cooling towers, boilers,industrial equipment including heat exchangers; in food serviceapplications, e.g., to treat water lines for coffee, espresso and teabrewers, espresso machines, ice machines, pasta cookers, water heaters,booster heaters, steam tables, grocery mister, steamers and/or proofers;in healthcare instrument care applications, e.g., soaking, cleaning,and/or rinsing surgical instruments, treating feed water to autoclavesterilizers; and in feed water for various applications such ashumidifiers, hot tubs, and swimming pools. In some embodiments, anapparatus of the present invention can be used to treat water providedto an ice machine.

Additional hard surface cleaning applications for the treated acidicwater source include clean-in-place systems (CIP), clean-out-of-placesystems (COP), automatic bottle washers, washer-decontaminators,sterilizers, textile laundry machines, ultra and nano-filtration systemsand indoor air filters. CIP systems include the internal components oftanks, lines, pumps and other process equipment used for processingtypically liquid product streams such as beverages, milk, juices. COPsystems can include readily accessible systems including wash tanks,soaking vessels, mop buckets, holding tanks, scrub sinks, vehicle partswashers, non-continuous batch washers and systems, and the like.

In additional aspects, use of a treated acidic water source according tothe invention reduces or eliminates use of additional chemistry streamsfor cleaning (e.g. polymers, threshold agents, etc.). Preferably, use ofa treated acidic water source according to the invention allows for theuse of specific environmentally friendly detersive compositions, e.g.,those substantially free of or free of builders, chelants, sequestrantsand/or phosphorous.

The various methods of use employing the acidic softened water accordingto the invention may be used in combination with any detersivecompositions. For example, a cleaning composition, a rinse agentcomposition and/or a drying agent composition can be combined withtreated water to form a use solution. The articles to be cleaned and/orrinsed are then contacted with the use solution. Exemplary detergentcompositions include ware washing detergent compositions, laundrydetergent compositions, CIP detergent compositions, environmentalcleaning compositions, hard surface cleaning compositions (such as thosefor use on counters or floors), motor vehicle washing compositions, andglass cleaning compositions. Exemplary rinse agent compositions includethose compositions used to reduce streaking or filming on a surface suchas glass. Exemplary drying agent compositions include dewateringcompositions. In the vehicle washing industry, it is often desirable toinclude a dewatering step where a sheeting or beading agent is appliedto the vehicle exterior.

However, according to a preferred embodiment the use of the treatedacidic water reduces and/or eliminates the need for additional cleaningcompositions (e.g. polymers, threshold agents, etc.) and/or reduces theoverall detergent consumption due to the increased cleaning efficacy ofthe treated water. Therefore, in some embodiments, the detersivecomposition for use with the methods of the present invention includes adetergent that is substantially free of a chelant, builder, sequestrant,and/or threshold agent, e.g., an aminocarboxylic acid, a condensedphosphate, a phosphonate, a polyacrylate, or the like. Without wishingto be bound by any particular theory, it is thought that because themethods and apparatus of the present invention reduce the negativeeffects of hardness ions in the water source, when used with adetergent, there is a substantially reduced or eliminated need toinclude chelating agents, builders, sequestrants, or threshold agents inthe detergent composition in order to handle the hardness ions.

For example, use of a water source treated in accordance with themethods of the present invention increases the efficacy of conventionaldetergents. It is known that hardness ions combine with soap anddetergents to form a scale or scum. Further, hardness ions limit theamount of lather formed with soaps and detergents. Without wishing to bebound by any particular theory, it is thought that by reducing theamount of these hardness ions the amount of these detrimental sideeffects can be reduced.

In some embodiments of use, there is a substantial reduction in thedetergent consumption as a result of the use of the treated acidic watersource for the cleaning application, including for example, at least a5% detergent consumption reduction, at least a 10% detergent consumptionreduction, at least a 20% detergent consumption reduction, or at least a25-30% detergent consumption reduction. Without being limited accordingto the invention, all percentages of detergent consumption reductionranges recited are inclusive of the numbers defining the range andinclude each integer within the defined range.

As one skilled in the art will ascertain, in some embodiments, thedetersive composition may include other additives, includingconventional additives such as bleaching agents, hardening agents orsolubility modifiers, defoamers, anti-redeposition agents, thresholdagents, stabilizers, dispersants, enzymes, surfactants, aestheticenhancing agents (i.e., dye, perfume), and the like. Adjuvants and otheradditive ingredients will vary according to the type of compositionbeing manufactured. It should be understood that these additives areoptional and need not be included in the cleaning composition. When theyare included, they can be included in an amount that provides for theeffectiveness of the particular type of component.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures, embodiments, claims, and examples described herein.Such equivalents are considered to be within the scope of this inventionand covered by the claims appended hereto. The contents of allreferences, patents, and patent applications cited throughout thisapplication are hereby incorporated by reference. The invention isfurther illustrated by the following examples, which should not beconstrued as further limiting.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

EXAMPLES

Embodiments of the present invention are further defined in thefollowing non-limiting Examples. It should be understood that theseExamples, while indicating certain embodiments of the invention, aregiven by way of illustration only. From the above discussion and theseExamples, one skilled in the art can ascertain the essentialcharacteristics of this invention, and without departing from the spiritand scope thereof, can make various changes and modifications of theembodiments of the invention to adapt it to various usages andconditions. Thus, various modifications of the embodiments of theinvention, in addition to those shown and described herein, will beapparent to those skilled in the art from the foregoing description.Such modifications are also intended to fall within the scope of theappended claims.

Example 1

Previous experiments show that ware washing results will be improvedusing softened water by conventional means and acidified by consumabledetergents and/or rinse additives. When conventional ion exchange resinsare exhausted, the water is no longer softened and brine is typicallyused to regenerate the resin. The water that is no longer softened oftencauses poor washing results unless additional detergents concentrationcontaining builders, chelants or polymers are increased and additionalrinse additive is used.

An experiment showing the proof of scale build up on ware was conductedusing a carbonate 500 ppm, 75 cycle test. Table 1 quantifies the resultsof ware treated according to the experiment, wherein Glasses 1A weretreated using only hard water (17 Grain/Gal hardness water) and Glasses1B were treated using the acidic softened water according to theinvention. The resultant scale build up on the treated ware surfaceswere depicted by photograph and measured visually according to thegrading scale (below).

The 75 cycle test employed was performed using six 10 oz. Libbey glassesand four plastic tumblers (SAN=Styrene Acrylonitrile) on a Hobart AM-14ware wash machine and 17 grain water (1 grain=17 ppm). Thespecifications of the Hobart AM-14 ware wash machine include: Washbathvolume: 60 L; Rinse volume: 4.5 L; Wash time: 40 sec.; Rinse time: 9sec.

Initially the glasses were cleaned according to procedures ensuringremoval of all film and foreign material from the glass surface. The 75cycle test was initiated. After the completion of each cycle, themachine is appropriately dosed (automatically) to maintain the initialconcentration. Glasses and tumbles dry overnight and then are graded forfilm accumulation using a strong light source. (1—No film; 2—Trace film;3—Light film; 4—Medium film; 5—Heavy film). As shown in Table 1, Glasses1A (hard water—17 grain) were graded a level 5, demonstrating heavyfilm. The glasses treated according to the invention shown in Glasses 1B(acidic softened water) were graded a level 1, demonstrating no film.

TABLE 1 Evaluated Glasses 1A 1B Film Accumulation 5 1

Example 2

An experiment showing the proof of protein removal on ware was conductedusing the detergent APEXNC 1000 ppm (Ecolab®) and the 7 cycles proteinremoval test. Table 2 show the results of ware treated according to theexperiment, wherein Glasses 2A were treated using only hard water (5Grain/Gal hardness water) and Glasses 2B were treated using the acidicsoftened water according to the invention. The resultant scale build upon the treated ware surfaces are depicted by photograph and measuredvisually according to the grading scale (below).

The 7 cycle protein test employed was performed to provide a genericmethod for evaluating glass filming, spotting, and soil removal in aninstitutional dish machine. Clean test glasses are washed in aninstitutional dish machine. The performance of the detergent or rinseaid is measured by the prevention of water spotting or filming and theremoval of soil from plastic tumblers and Libbey Glass tumblers.According to this experimentation the performance of use of softenedacid water (as opposed to 5 grain hard water) were evaluated.

Clean Libbey glasses were used for each test product and new plastictumblers were used for each experiment. Food soils were prepared foodsoils. The dish machine was filled with the tested water sources(described according to Glasses 2A-2B) and heaters were turned on. Thefinal rinse temperature was adjusted to 180° F. for the high temperaturemachines. Glasses and plastic tumblers were soiled and placed in theoven at 160° F. for 8 minutes. While glasses were drying, the ware washmachine was primed with 120 g of soil previously prepared (correspondingto 2000 ppm of food soil in the sump). Soiled glasses/plastic tumblersare placed in the rack beside the re-deposition glasses/plastictumblers. The wash machine is started and glasses are run through anautomatic cycle. When the cycle has ended, the top of the glasses aremopped with a dry towel. The soiling procedure is repeated. At thebeginning of each cycle, the appropriate amount of detergent and foodsoil are added to the wash tank to make up for the rinse dilution. Thesteps are repeated until seven cycles are complete.

Results were evaluated using the de-staining methods employing aCoomassie Blue R Stain solution to evaluate glasses visually against awhile background. Glasses are first stained using the Coomassie Blue RStain solution and rinsed thoroughly with de-staining solution (methanoland acetic acid in distilled water). Each glass is then visually ratedin a viewing area against a white background, wherein residual proteinremains stained blue. (1—No protein; 2—20% of glass surface covered inprotein; 3—40% of glass surface covered in protein; 4—60% of glasssurface covered in protein; 5—greater than 80% of glass surface coveredin protein As shown in Table 2 the Glasses 2A (hard water—5 grain) weregraded a level 2, demonstrating 20% of glass surface covered in protein.The glasses treated according to the invention shown in Glasses 2B(acidic softened water) were graded a level 1, demonstrating no proteinon the glasses.

TABLE 2 Evaluated Glasses 2A 2B Film Accumulation 2 1

Example 3

The capacity of a commercially-available weak acid resin against pH ofwater was tested. An Amberlite® IRC 76 ion exchange resin(commercially-available from Rohm and Haas Company) was tested.Amberlite® IRC 76 ion exchange resin is one example of acommercially-available weak acidic resin having a polyacrylic copolymerwith carboxylic acid functional group. This particular resin ischaracterized by a volume variation smaller than conventional weak acidresins and can be used in H⁺, Na⁺ or NH₄ ⁺ forms and can also be used toremove bicarbonate hardness from water. The resin is known to besensitive to chlorine in water (affecting the lifetime and performanceof the resin). The operating capacity of the resin is a function ofanalysis, temperature and service flow rate of water. The resin isreadily regenerated with little over stoichiometric amounts of strongacids.

On average, the use of a conventional weak acid resin used in ionexchange water softening applications are designed for bed depths of 2.6feet for water treatment rates of about 2 to about 20 gallons perminute. However, one skilled in the art may vary the water treatmentrates, including for example from about 0.5 to about 50 gallons perminute. The configuration used for the testing of the capacity of theion exchange resin used a flow rate of about 5-10 gallons of water perminute and consumed less than 1 cubic foot of resin for the system. Inaddition, various monitoring devices were in use within the system tomeasure flow, water hardness (e.g. hardness ions measured by titrationmethod), pressure within the system (e.g. measurement of presumerequired for effective

e rinsing, preferably pressure measurement of about 20 psi), pH of theeffluent (e.g. electrode measurement), and TDS (e.g. ICP analyticalmethod for TDS).

FIG. 6 shows a diagram of the capacity of an acid regenerated ionexchange resin v. pH of treated water according to an embodiment of theinvention. The best results are obtained from the resin with a pH lessthan about 6. Preferably the pH is less than about 7.

Example 4

The capacity of a commercially available weak acid resin againsthardness of water was tested. An Amberlite® IRC 76 ion exchange resin(commercially-available from Rohm and Haas Company) was tested.Amberlite® IRC 76 ion exchange resin is one example of acommercially-available weak acidic resin having a polyacrylic copolymerwith carboxylic acid functional group. This particular resin ischaracterized by a volume variation smaller than conventional weak acidresins and can be used in H⁺, Na⁺ or NH₄ ⁺ forms and can also be used toremove bicarbonate hardness from water. The resin is known to besensitive to chlorine in water (affecting the lifetime and performanceof the resin). The operating capacity of the resin is a function ofanalysis, temperature and service flow rate of water. The resin isreadily regenerated with little over stoichiometric amounts of strongacids.

The configuration used for the testing of the capacity of the ionexchange resin used a flow rate of about 5-10 gallons of water perminute and consumed less than 1 cubic foot of resin for the system. Inaddition, various monitoring devices were in use within the system tomeasure flow, water hardness (e.g. hardness ions measured by titrationmethod), pressure within the system (e.g. measurement of presumerequired for effective rinsing, preferably pressure measurement of about20 psi), pH of the effluent (e.g. electrode measurement), and TDS (e.g.ICP analytical method for TDS).

FIG. 7 shows a diagram of the capacity of an acid regenerated ionexchange resin v. water hardness of treated water according to anembodiment of the invention. The best results are obtained from theresin system with a water hardness less than about 2 grains.

Example 5

Layered resin bed systems were evaluated to assess the impact on treatedwater hardness using more than one acid cation exchange resin. 4710grams of the Dowex® MAC-3 weak cation exchange resins(commercially-available from Dow Chemical Company) were used to form alayered bed using two of the weak acid cation exchange resins, such asshown in FIG. 3A. The Dowex® MAC-3 LB resin is one example of acommercially-available weak acidic resin having a carboxylic acidfunctional groups. The MAC-3 WAC resins were packed into two connected19 inch by 5 inch diameter housing tubes. 3575 grams of the Dowex® MAC-3weak cation exchange resin (commercially-available from Dow ChemicalCompany) and 1235 grams of Dowex® Marathon-C (H form) strong cationexchange resin (commercially-available from Dow Chemical Company) wereused to form a mixed layered bed, such as shown in FIG. 3B. The cationexchange resins were packed into two connected 19 inch by 5 inchdiameter housing tubes.

Hard water (17 grains) was provided to the layered resin bed systemsdepicted in FIGS. 3A-3B at a controlled rate of about 0.8 gallons perminute. The water from the outlet of the second treatment reservoir wasmeasured for both hardness and pH. Water samples were taken to test pHlevels against capacity.

FIG. 8 shows a diagram of the capacity of the layered bed systems. Asshown, the layered weak acid regenerated ion exchange resin providedsoftened water having between about 0.5 to 1 grains, whereas the layeredmixed bed of weak acid regenerated ion exchange resin and a strong acidregenerated ion exchange resin provided softened water having 0 grainhardness. The use of the layered mixed bed employing the strong acidcation exchange resin provided greater reduction in water hardness,despite its overall lower capacity for reducing water hardness if usedalone. However, the water softened using the layered weak acidregenerated ion exchange resins provided the additional benefit ofproviding reduced pH softened water, which provides additional cleaningbenefits.

As shown in the figure, each of the layered beds demonstrated softeningefficacies sustained for at least about 150 gallons of treated water.Thereafter between about 150 gallons to 200 gallons the resins becameexhausted and were unable to continue to sufficiently remove waterhardness. According to aspects of the invention, for the evaluated watertreatment apparatuses in this Example, the use of acid regenerationwould need to be employed after about 150 gallons of treated water.

FIG. 9 shows a diagram of the pH versus the capacity of the layered bedsystems. As shown, the layered weak acid ion exchange resin bed (i.e.employing a single type of resin) resulted in less acidified treatedwater source as the capacity of the system was tested. Namely, aboveabout 200 gallons of treated water, the pH of the single resin layeredbed began to increase above about 4, whereas the layered mix resin bedsystem maintained a constant acidified water having a pH between about 3to about 3.5.

Example 6

The use of an acid regenerant according to embodiments of the inventionwere analyzed. A single weak acid resin bed, such as disclosed inExample 4 was regenerated using various acid regenerants disclosedherein. It was found that the regeneration process is initiallydominated by thermodynamics. A regenerant with a sufficiently low pHwill drive the process over the energy barrier, showing a fast pH dropat the first several minutes. Thereafter, the regeneration process iscontrolled by kinetics. This requires a regenerant to be used for asufficient amount of time (e.g. about 5 to about 90 minutes) to drivethe regeneration of the resin to completion.

As shown in FIGS. 10A-B the use of a strong acid regenerant (HCL 0.38M(FIG. 10A), HCL 1.8M (FIG. 10B)) is required to sufficiently decreasethe pH in the weak acid resin. According to embodiments of the inventionthe concentration of the acid regenerant used in the regeneration cyclewill depend upon the molarity of the acid employed. In some embodiments,the concentration of the acid used in a solution for providing the acidregenerant to the ion exchange resin is from about 1% to about 20%, fromabout 2% to about 10%, or about 10% for regeneration.

After the resin has been regenerated, as shown in FIGS. 10A-B, anexemplary service cycle (i.e. treating hard water with the acidregenerated resin) can be used to again provide a treated acidifiedwater source. As shown in FIG. 11, the use of the strong acid regenerantof FIG. 10B provides superior treatment capacity for a longer servicecycle.

Example 7

The use of additional acid regenerants was evaluated pursuant to theresults of Example 6. The following acid regenerants were employed andreported in equivalence of the various acids employed: 1.2 eq sulfuricacid, 1.2 eq urea sulfate, 1.2 eq hydrochloric acid, 1.2 eq MSA, and 1.4eq citric acid. FIG. 12 shows the drop in pH of the resin during aregeneration step employing the various acid regenerants. Beneficially,the use of equivalence of the various acids employed in this examplestakes into account the various fluctuating factors, including forexample, the size of the system, amount of hardness to be removed, etc.

After the resin has been regenerated, as shown in FIG. 12, an exemplaryservice cycle (i.e. treating hard water with the acid regenerated resin)was employed to determine the efficacy of service cycles, as measured bywater hardness of the treated water source, based on the use of thevarious acid regenerants. As shown in FIG. 13, the service cycle ofvarious acid regenerant provided treated acidic water having a hardnessof about 1 or less than about 1 for at least 100 gallons of treatedwater.

The inventions being thus described, it will be obvious that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the inventions and all suchmodifications are intended to be included within the scope of thefollowing claims.

What is claimed:
 1. A method for treating hard water using an acidregenerated ion exchange resin comprising: contacting a hard watersource with a water treatment composition placed in front of a dilutionsystem in a service cycle, wherein the water treatment compositioncomprises at least one ion exchange resin, wherein the ion exchangeresin generates a treated water source by exchanging protons on saidresin for dissolved cations including water hardness ions and totaldissolved solids in said water source, and wherein said ion exchangeresin is regenerated using an acid; generating the service cycle treatedwater source comprising softened, acidic and low total dissolved solids(TDS) water having a hardness level of less than about 2 grains pergallon (gpg) and a pH less than about 6, wherein the treated watersource may be used for washing and/or rinsing in a variety of cleaningapplications; and regenerating the ion exchange resin upon exhaustionusing an acid regenerant.
 2. The method according to claim 1, whereinsaid ion exchange resin is a weak acid cation exchange resin selectedfrom the group consisting of a cross-linked polyacrylic with carboxylicacid functional group, a cross-linked polymethacrylic with carboxylicacid functional group and mixtures of thereof, and/or a strong acidcation exchange resin selected from the group consisting of apolystyrene with sulfonic acid functional group, a polystyrene withsulfonic acid functional group and mixtures of thereof.
 3. The methodaccording to claim 2, wherein said ion exchange resin is a layered bedsystem employing at least two of said cation exchange resins.
 4. Themethod according to claim 1, further comprising measuring pH and/orproton concentration and/or total dissolved solids within the watertreatment composition, water source and/or treated water source, andtriggering an event as a result of the obtained measurement.
 5. Themethod according to claim 4, wherein a pH and/or proton concentrationmeasurement is obtained from said treated water source.
 6. The methodaccording to claim 4, wherein a differential pH and/or protonconcentration measurement is obtained from said water source and saidtreated water source.
 7. The method according to claim 4, wherein thetriggered event is selected from the group consisting of regeneratingthe resin of the water treatment component, varying a detergent or otherchemistry addition to the treated water source and combinations thereof.8. The method according to claim 7, wherein the regeneration of theresin is triggered and comprises providing an acid regenerant to theresin, displacing water hardness ions on the resin with protons from theacid regenerant, and generating a regeneration step effluent water. 9.The method according to claim 8, wherein the effluent water is put to awaste stream.
 10. A method for treating hard water using an acidregenerated ion exchange resin comprising: contacting a hard watersource with a water treatment composition placed in front of a dilutionsystem in a service cycle, wherein said dilution system is an aspiratoror other pump that feeds into a cleaning system, wherein the watertreatment composition comprises at least one ion exchange resin, whereinthe ion exchange resin generates a treated water source by exchangingprotons on said resin for dissolved cations including water hardnessions and total dissolved solids in said water source, and wherein saidion exchange resin is regenerated using an acid; generating the servicecycle treated water source comprising softened, acidic and low totaldissolved solids (TDS) water having a hardness level of less than about2 grains per gallon (gpg) and a pH less than about 6, wherein thetreated water source may be used for washing and/or rinsing in a varietyof cleaning applications; and regenerating the ion exchange resin uponexhaustion using an acid regenerant.